实现SwipeRefreshLayout首次进入自动刷新

先来一张效果图



实现方式：

方法一、

①在onWindowFocusChanged()方法中，设置为刷新状态为true

@Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
mSwipeRefreshLayout.setRefreshing(true);
}

②在获取数据完成后设置刷新状态为false

if (mSwipeRefreshLayout.isRefreshing()) {
mSwipeRefreshLayout.setRefreshing(false);
}

方法二、

①调用mSwipeRefreshLayout.measure()方法后，设置刷新状态为true

//手动调用,通知系统去测量
mSwipeRefreshLayout.measure(0,0);
mSwipeRefreshLayout.setRefreshing(true);

②在获取数据完成后设置刷新状态为false

if (mSwipeRefreshLayout.isRefreshing()) {
mSwipeRefreshLayout.setRefreshing(false);
}

说明：

方法一和方法二的第一步的目的，都是为了在SwipeRefreshLayout绘制完成之后，再设置刷新状态为true，否则大多数情况下，SwipeRefreshLayout刷新球会不显示。

源码：

package org.raphets.swiperefreshlayoutdemo;

import android.graphics.Color;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
private SwipeRefreshLayout mSwipeRefreshLayout;
private TextView mTextView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.srl);
mTextView = (TextView) findViewById(R.id.tv);

//设置刷新球颜色
mSwipeRefreshLayout.setColorSchemeColors(Color.BLUE, Color.RED, Color.YELLOW);
mSwipeRefreshLayout.setProgressBackgroundColorSchemeColor(Color.parseColor("#BBFFFF"));
//手动调用,通知系统去测量
//        mSwipeRefreshLayout.measure(0,0);
mSwipeRefreshLayout.setRefreshing(true);
getData();
}

/**
* 模拟网络请求
*/
private void getData() {
new Thread() {
@Override
public void run() {
super.run();
//模拟网络请求
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//在UI线程中更新UI
runOnUiThread(new Runnable() {
@Override
public void run() {
mTextView.setText("首次进入自动刷新");
if (mSwipeRefreshLayout.isRefreshing()) {
mSwipeRefreshLayout.setRefreshing(false);
}
}
});
}
}.start();
}

@Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
mSwipeRefreshLayout.setRefreshing(true);
}
}